Swift ObjectMapper: How to parse array inside of an array - ios

Question

This is my JSON response:
[
[
{
"id": 22,
"request_id": "rqst5c12fc9e856ae1.06631647",
"business_name": "Code Viable",
"business_email": "code#viable.com",
"title": "Apache Load/Ubuntu",
}
],
[
{
"id": 24,
"request_id": "rqst5c130cae6f7609.41056231",
"business_name": "Code Viable",
"business_email": "code#viable.com",
"title": "Load",
}
]
]
This JSON structure got an array inside of an array, the object of the inner array is what I am trying to parse. Here is the my mapper:
struct JobResponseDataObject: Mappable {
init?(map: Map) {
}
var id: Int?
var requestId: String?
var businessName: String?
var businessEmail: String?
mutating func mapping(map: Map) {
id <- map["id"]
requestId <- map["request_id"]
businessName <- map["business_name"]
businessEmail <- map["business_email"]
}
}
I have tried create another mapper struct to hold the array of objects [JobResponseDataObject] and use Alamofire's responseArray with it, but it didn't work. I have also tried prefixing my json id with 0. but that didn't work too. Please help
Thank

Answer 1

So here's the deal...Codable is a pretty cool protocol from Apple to handle parsing JSON responses from APIs. What you're getting back is an array of arrays, so your stuff's gonna be look like this:
[[ResponseObject]]
So anyway, you'd make a struct of your object, like so:
struct ResponseObject: Codable {
let id: Int?
let requestId: String?
let businessName: String?
let businessEmail: String?
let title: String?
}
You'll note I changed the key name a bit (instead of request_id, I used requestId). The reason is JSONDecoder has a property called keyDecodingStrategy which presents an enum of canned decoding strategies you can select from. You'd do convertFromSnakeCase.
Here's code you can dump into a playground to tinker with. Basically, declare your struct, match it up to whatever the keys are in your JSON, declare a decoder, feed it a decoding strategy, and then decode it.
Here's how you could do an Alamofire call:
private let backgroundThread = DispatchQueue(label: "background",
qos: .userInitiated,
attributes: .concurrent,
autoreleaseFrequency: .inherit,
target: nil)
Alamofire.request(url).responseJSON(queue: backgroundThread) { (response) in
guard response.result.error == nil else {
print("💥KABOOM!💥")
return
}
if let data = response.data {
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
do {
let parsedResponse = try decoder.decode([[ResponseObject]].self, from: data)
print(parsedResponse)
} catch {
print(error.localizedDescription)
}
}
}
Here's code you can chuck in a playground.
import UIKit
let json = """
[
[
{
"id": 22,
"request_id": "rqst5c12fc9e856ae1.06631647",
"business_name": "Code Viable",
"business_email": "code#viable.com",
"title": "Apache Load/Ubuntu",
}
],
[
{
"id": 24,
"request_id": "rqst5c130cae6f7609.41056231",
"business_name": "Code Viable",
"business_email": "code#viable.com",
"title": "Load",
}
]
]
"""
struct ResponseObject: Codable {
let id: Int?
let requestId: String?
let businessName: String?
let businessEmail: String?
let title: String?
}
if let data = json.data(using: .utf8) {
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
do {
let parsedResponse = try decoder.decode([[ResponseObject]].self, from: data)
print(parsedResponse)
} catch {
print(error.localizedDescription)
}
}

Answer 2

You should use this JobResponseDataObject struct as [[JobResponseDataObject]] instead of [JobResponseDataObject] - where you are making a property using this struct in your parent struct or class.

Answer 3

You can use Codable here for mapping the JSON response, The JobResponseDataObject struct should look like,
struct JobResponseDataObject: Codable {
var id: Int?
var requestId: String?
var businessName: String?
var businessEmail: String?
var title: String?
private enum CodingKeys: String, CodingKey {
case id = "id"
case requestId = "request_id"
case businessName = "business_name"
case businessEmail = "business_email"
case title = "title"
}
}
let json = JSON(responseJSON: jsonData)
do {
if let value = try? json.rawData(){
let response = try! JSONDecoder().decode([[JobResponseDataObject]].self, from: value)
}
} catch {
print(error.localizedDescription)
}